I'm looking for some help here - so I'm a grad student and stats newbie (but trying to move on from newbie status!) and attempting to figure out how to conduct the analyses I'm interested in but I'm feeling very lost.
I'm looking to do MLM with a large RCT (N=434) with the active treatment vs. services as usual (i.e., 2 treatment conditions), and I have four total timepoints - baseline, posttreatment, 6 months follow-up, and 12 months follow-up. The main purpose of the study is to look at gender as a moderator of treatment outcomes, and a secondary goal is to look at whether there are differences in mechanisms/mediators of treatment effects by gender as well. I spoke with a professor in the quant psychology department about my project and he mentioned that the strength of my project is that I have follow-up data with such a large sample (and high retention rates) with a marginalized, hard-to-reach population - so he suggested using MLM. Typically, when I've used MLM in the past, I've done it with looking at clusters or within/between individual change across multiple timepoints. But is there a way to use MLM to address my research questions - 1) to look at gender as a moderator of intervention outcomes in this large-scale RCT, and 2) to look at whether hypothesized, female-specific mediators of change are indeed more predictive of improved treatment outcomes for females relative to males? I'm feeling a little lost as to what would be my level 1 vs level 2 variables here.
Any help would be greatly appreciated!! Thank you so much!!